Intramedullary Rod Implantation System

ABSTRACT

A system for implanting a prosthetic device with an opening into a bone includes a plug that is removably received within the opening of the prosthetic device. The system also includes a bone removal tool that advances into the bone from outside the bone and that removes a portion of the bone while advancing into the bone to reveal the plug. The bone removal tool includes a plug engaging portion that engages with the plug. The bone removal tool at least partially removes the plug from the opening of the prosthetic device while engaged with the plug. Moreover, the system includes an alignment system that detects whether the bone removal tool and the plug are substantially axially aligned.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/871,432 filed Aug. 30, 2010. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The following relates to an intramedullary rod and, more specifically,relates to an intramedullary rod implantation system.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Prosthetic devices can be implanted in a patient's body in a variety ofways. For instance, some prosthetic devices include portions that areimplanted in the intramedullary (IM) canal of a bone. In one specificexample, a femoral component of a hip joint prosthesis can include an IMrod that is implanted coaxially within the IM canal of a resected femur.Also, fasteners can extend through the cortical and cancellous materialof the femur, transverse to the axes of the rod and femur, and thefasteners can extend into respective holes that are formed in the rod.Accordingly, the IM rod can be frictionally fit within the IM canal, andthe fasteners can further secure the IM rod to the femur.

During the implantation procedure, after the IM rod is implanted in theIM canal, holes can be drilled transversely through the cortical andcancellous material of the femur to reveal the holes in the IM rod andto provide access for the transverse fasteners. However, determiningwhere to drill can be difficult. Accordingly, the following disclosurerelates to a system for more easily determining where to drill toprovide access to the transverse holes.

SUMMARY

A system for implanting a prosthetic device into a bone is disclosed.The prosthetic device has an opening that is disposed in the bone. Thesystem includes a plug that is removably received within the opening ofthe prosthetic device. The system also includes a bone removal tool thatadvances into the bone from outside the bone and that removes a portionof the bone while advancing into the bone to reveal the plug. The boneremoval tool includes a plug engaging portion that engages with theplug. The bone removal tool at least partially removes the plug from theopening of the prosthetic device while engaged with the plug. Moreover,the system includes an alignment system that detects whether the boneremoval tool and the plug are substantially axially aligned.

In addition, a method of implanting a prosthetic device into a bone isdisclosed. The method includes inserting the prosthetic device into thebone. The prosthetic device includes an opening and a plug removablyreceived within the opening. The method also includes detecting whethera bone removal tool outside the bone and the plug are substantiallyaxially aligned. Moreover, the method includes advancing the boneremoval tool from outside the bone into the bone to remove a portion ofthe bone and to reveal the plug. Additionally, the method includesengaging the bone removal tool and the plug, and removing the plug fromthe opening of the prosthetic device at least partially while the boneremoval tool is engaged with the plug.

Still further, a system for implanting a prosthetic device into a boneis disclosed. The system includes an intramedullary (IM) rod that isoperable to be implanted in an IM canal of a femur, a tibia, or ahumerus. The IM rod has a longitudinal axis and a through hole thatextends transverse to the longitudinal axis. The system also includes aplug that is threadably engaged to the IM rod within the through hole ina first rotational direction. The system also includes a bone removaltool that rotates in a second rotational direction. The secondrotational direction is opposite from the first rotational direction.The bone removal tool advances through the bone from outside the bone ina first linear direction and removes a portion of the bone whilerotating in the second rotational direction and while advancing into thebone in a first linear direction to reveal the plug. The bone removaltool includes a barb that embeds within and engages with the plug. Thebone removal tool at least partially threadably disengages the plug fromthe through hole of the IM rod while rotating in the second rotationaldirection and while embedded within the plug. Moreover, the systemincludes an alignment system that detects whether the bone removal tooland the plug are substantially axially aligned. The alignment systemincludes an ultrasound system and/or a proximity sensor, and thealignment system includes a power generating device that generates powerfrom rotation of the bone removal tool to power the alignment system. Inaddition, the system includes a feedback device that indicates that thebone removal tool and the plug are substantially axially aligned. Also,the system includes a fastener that extends into the bone and into theopening to secure the IM rod to the bone.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is an exploded, perspective view of a system for implanting aprosthetic device according to various embodiments of the presentdisclosure;

FIG. 2 is an assembled, perspective view of the system of FIG. 1;

FIG. 3 is a sectional view of the system of FIG. 1, wherein a boneremoval tool is shown removing a portion of bone in order to reveal aplug within an intramedullary rod;

FIG. 4 is a sectional view of the system of FIG. 1, wherein the boneremoval tool of FIG. 3 is shown engaged with the plug and removing theplug from the IM rod;

FIG. 5 is a partial sectional view of the system according to variousadditional exemplary embodiments, wherein a plug is shown before beingcoupled to an intramedullary (IM) rod;

FIG. 6 is a partial sectional view of the system of FIG. 5, wherein theplug is shown coupled to the IM rod;

FIG. 7 is a partial sectional view of the system according to variousadditional exemplary embodiments, wherein a plug is shown before beingcoupled to an IM rod;

FIG. 8 is a partial sectional view of the system of FIG. 7, wherein theplug is shown coupled to the IM rod; and

FIG. 9 is a perspective view of a plug of the system according tovarious additional embodiments of the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.Moreover, while the exemplary embodiments herein are directed to anintramedullary rod, the present disclosure can be directed to anyimplant having openings that need to be located for implantation. Itshould be further understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

Referring initially to FIG. 1, a system 10 for implanting a prostheticdevice 12 into a bone 14 is illustrated, according to various exemplaryembodiments of the present disclosure. In the embodiments illustrated,the prosthetic device 12 can be an elongated implant, such as anintramedullary (IM) rod 16 for a femoral implant of a prosthetic jointassembly. However, it will be appreciated that the device 12 can be astem, a segmented replacement, a modular implant, or any otherprosthetic device 12 that is implanted in a femur or any other bone.

The IM rod 16 can be elongate and can have a substantially straight orcurved longitudinal axis X. The rod 16 can include a proximal end 18 anda distal end 20. Furthermore, the IM rod 16 can include a neck 22, whichis disposed on the proximal end 18. The neck 22 can receive a head (notshown), which is received for rotation within an acetabular cup (notshown) of the patient. Other configurations of an IM rod 16 can also beemployed without departing from the scope of the present disclosure.

As shown in FIG. 1, the IM rod 16 can also include at least onetransverse opening 24. In some embodiments, the IM rod 16 can includetwo or more openings 24, and the openings 24 can be disposed between theproximal and distal ends 18, 20. Furthermore, the openings 24 can bethrough holes that extend transverse (e.g., perpendicular) to the axis Xof the rod 16. In other embodiments, the openings 24 can extend throughthe rod 16 at any suitable acute angle relative to the axis X of the rod16. The openings 24 can be internally threaded. It will be appreciatedthat the openings 24 can be of any suitable type other than throughholes (e.g., elongated slots, etc.). Also, it will be appreciated thatthere can be any number of openings 24 in the rod 16.

As shown in FIG. 2, the rod 16 can be inserted into an IM canal 26within a resected femur 28. In order to further secure the rod 16 to thefemur 28, fasteners 30 can each extend transversely through cortical andcancellous bone of the femur 28 and into a respective opening 24. Insome embodiments, the fasteners 30 can be threaded fasteners (e.g.,screws, etc.) and can threadably engage to the rod 16 within thethreaded openings 24. The fasteners 30 can be of any suitable type otherthan threaded fasteners 30 (e.g., transverse pins, etc.).

It will again be appreciated that the system 10 can be used forimplanting any type of prosthetic device 12 other than a femoralimplant. Also, it will be appreciated that the system 10 can be used forimplanting a prosthetic device 12 into any bone 14 other than a femur28. For instances, the system 10 can be used for implanting a prostheticdevice 12 into a tibia or humerus without departing from the presentdisclosure. Moreover, it will be appreciated that the system 10 can beused for implanting any prosthetic device 12 into any location in a bone14 other than an IM canal 26.

In order to implant the prosthetic device 12, the femur 28 can beresected, and the rod 16 can be driven longitudinally into the canal 26.Then, a bone removal tool 34, such as a drill bit 36, mill, or othersuitable tool, can be used to remove bone and form holes to reveal andprovide access for the fasteners 30 to extend into the openings 24. Morespecifically, the drill bit 36 can rotate about its axis to advancethrough the bone 14 from outside the bone 14 and to remove a portion ofthe bone 14 to reveal one of the openings 24.

To assist the user in locating the openings 24 before drilling, thesystem 10 can include plugs 32, which are removably and threadablyreceived within the openings 24. In some embodiments, the system 10 caninclude a plug 32 for each opening 24. The plugs 32 can be attached tothe rod 16 within the respective openings 24 before the rod 16 isinserted within the canal 26 and before drilling.

Moreover, the system 10 can include an alignment system 38 that detectswhether the bone removal tool 34 and any of the plugs 32 aresubstantially axially aligned, as will be discussed in greater detailbelow. Accordingly, the system 10 can assist the surgeon when attemptingto align the bone removal tool 34 and the plugs 32, and the system 10can allow the surgeon to implant the rod 16 in the bone 14 more quickly,conveniently, and accurately as will be discussed.

Referring now to FIGS. 1-4, the plugs 32 will be discussed in greaterdetail. As shown, the plugs 32 can be substantially cylindrical and canbe either solid or hollow. The plugs 32 can be made out of any suitablematerial. For instance, the plugs 32 can include an ultrasonicallysensitive material (e.g., magnesium, cobalt chrome, alloys thereof,etc.) or any other suitable material. In some embodiments, the plugs 32can be made of a material that is different from the rod 16 such thatthe plugs 32 can be distinguished from the rod 16 using ultrasound aswill be discussed in greater detail below. Also, the plugs 32 can bemade out of a pierceable, malleable, or deformable material (e.g.,Delrin, nylon, etc.) such that the drill bit 36 can embed within theplugs 32 as will be discussed in greater detail below. Furthermore, theplugs 32 can be threaded so as to threadably engage to the rod 16 withinthe openings 24. In some embodiments, the plugs 32 can includeself-tapping threads. It will be appreciated, however, that the plugs 32can be removably coupled to the rod 16 in any other suitable fashion.Also, the plugs 32 can be attached to the rod 16 and shipped as such bythe manufacturer or the plugs 32 can be attached to the rod 16 by thesurgeon or other medical professional (e.g., intra-operatively).

In addition, the drill bit 36 can include sharpened flutes 40 thatextend helically about the axis at the drill bit 36. Also, the drill bit36 can be a commercially available drill bit 36 that has been modifiedto include features discussed below. During operation, the drill bit 36can rotate about its longitudinal axis, and can drill through and removeportions of the bone 14 to form holes therein.

As best shown in FIGS. 3 and 4, the drill bit 36 can include a plugengaging portion, such as one or more barbs 44 that extend from aterminal distal end 42 of the drill bit 36. The barbs 44 can allow thedrill bit 36 to engage with the plug 32 (FIG. 4) and embed into the plug32. As will be discussed, when the drill bit 36 is engaged with the plug32, the drill bit 36 can be used to at least partially remove the plug32 from the opening 24. It will be appreciated that the drill bit 36 caninclude any suitable plug engaging portion other than the barbs 44without departing from the scope of the present disclosure. Forinstance, the drill bit 36 can include a helical projection that piercesand embeds within the plug 32, the drill bit 36 can includesconventional flutes that embed within the plug 32, or the drill bit 36can include any other suitable feature for embedding within the plug 32.

As shown in FIG. 4, the plugs 32 can be threadably engaged to the rod 16in the opening 24 in a first rotational direction R1, and the drill bit36 can drill in the bone 14 by rotating in a second rotational directionR2, and the first and second rotational directions R1, R2 can beopposite to each other. More specifically, in some embodiments, thethreading on the plug 32 and in the opening 24 can be left-handedthreading, and the flutes 40 on the drill bit 36 can be right-handedfluting.

Thus, as shown in FIG. 3, the drill bit 36 can be advanced in a firstlinear direction D1 and rotated in the second (right-handed) rotationaldirection R2 to tunnel into the bone 14 and to advance toward the plug32. As shown in FIG. 4, upon reaching the plug 32, the drill bit 36 canembed within the plug 32 by way of the barbs 44. Because of theleft-handed threading in the first rotational direction R1 of the plug32 and opening 24, the right-handed rotation of the drill bit in thesecond rotational direction R2 can cause the plug 32 to be backed out ofthe opening 24 and to move at least partially in the second lineardirection D2, away from the rod 16. Therefore, the drill bit 36, itself,can be used to remove the plug 32. (In other words, the drill bit 36 candrill into the bone 14 toward the plug 32 in the first linear directionD1 (FIG. 3), and the drill bit 36 and the plug 32 can be backed out ofthe bone 14 in the second, opposite linear direction D2 (FIG. 4) bycontinuing the rotation of the drill bit 36 in the second rotationaldirection R2).

It will be appreciated that the fluting on the drill bit 36 can beleft-handed without departing from the scope of the present disclosure.Likewise, it will be appreciated that the threading on the plug 32 andopening 24 can be right-handed without departing from the scope of thepresent disclosure.

Referring now to FIGS. 1 and 2, the alignment system 38 will bediscussed in greater detail. In some embodiments, the alignment system38 can include an ultrasound system 45. The ultrasound system 45 can beoperably coupled to the bone removal tool 34. The ultrasound system 45can also include a display 46 and a processor 52. As shown in FIG. 2,the ultrasound system 45 can generate and emit an ultrasound signaldirected away from the drill bit 36 and in an axial direction of thedrill bit 36. Accordingly, the ultrasonic signal generated by the system45 can reflect from the bone 14, the rod 16, and the plug 32, and thereflected signal can be received by the ultrasound system 45 andprocessed by the processor 52 to create an image that is displayed onthe display 46.

As mentioned above, the plug 32 can be made of and/or include anultrasonically detectable material, such as magnesium, cobalt chrome, orany other alloy thereof. Also as mentioned, the plug 32 can be made of amaterial that is different from the material of the rod 16. Thus, theplug 32 can have a different ultrasonic signature from adjacent areas ofthe rod 16, the bone 14, etc. due to the presence of the ultrasonicallydetectable material in the plug 32. For instance, the plug 32 can have adifferent contrast on the display 46 from adjacent areas of the rod 16and bone 14. With the image on the display 46, the user can determinewhether the drill bit 36 and the plug 32 are substantially axiallyaligned in real time. Once aligned, the drill bit 36 can be used todrill into the bone 14 and remove the plugs 32, as discussed above.

In addition to or as an alternative to the ultrasound system 45, thealignment system 38 can include a proximity sensor system 47 (e.g., RFIDsystem). For instance, in some embodiments, the proximity sensor system47 can include a signal generator 48 that is operatively coupled to theplug 32 or the drill bit 36. As shown in FIGS. 3 and 4, the signalgenerator 48 can be enclosed within or otherwise operably coupled to theplug 32. Moreover, the alignment system 38 can include a receiver 50.The signal generator 48 can generate and emit a radio frequency (RF)signal at any suitable frequency, and the receiver 50 can receive theradio signal that is emitted when the receiver 50 is in relatively closeproximity (e.g., aligned with and disposed just outside the bone 14).Moreover, the processor 52 can process the signal received by thereceiver 50 to thereby automatically detect that the drill bit 36 issubstantially aligned with the plug 32.

The signal generator 48 can be a passive element (e.g., includes nopower source), and the receiver 50 can be a transceiver that emits anelectromagnetic field that causes the signal generator 48 to generate acurrent, thereby causing the signal generator 48 to emit the RF signaldescribed above. In other embodiments, the signal generator 48 can be anactive element (e.g., includes a power source) that independentlygenerates and transmits the RF signal described above.

Thus, assuming that the signal generator 48 is a passive element, theuser can move the drill bit 36 relative to the plug 32, and when thedrill bit 36 is misaligned and spaced from the plug 32 (shown in phantomin FIG. 2), the signal generator 48 will not emit the RF signal;however, when the drill bit 36 is substantially axially aligned with theplug 32 just outside the bone 14 (shown in solid lines in FIG. 2), thesignal generator 48 will emit the RF signal, and the receiver 50 willreceive the signal emitted by the generator 48. As a result, theprocessor 52 processes the signal received by the receiver 50 to detectthat the drill bit 36 is in axial alignment with the plug 32.

It will be appreciated that the alignment system 38 can include anysuitable means for detecting alignment of the drill bit 36 and the plug32 without departing from the scope of the present disclosure. Forinstance, the alignment system 38 can include any suitable means inaddition to or instead of the ultrasonic system and the proximity sensorsystem described above.

As shown in FIGS. 1 and 2, the system 10 can also include a feedbackdevice 54. The feedback device 54 can include an indicator 56. Theindicator 56 of the feedback device 54 can selectively provide afeedback signal to indicate that the drill bit 36 is substantiallyaligned with the plug 32. The indicator 56 can provide a visual feedbacksignal (e.g., a light, etc.), an audible signal (e.g., a sound, etc.),and/or a tactile feedback signal (e.g., vibration, etc.). However, itwill be appreciated that the feedback device 54 can provide any suitablefeedback signal and/or any combination of feedback signals. In someembodiments, the indicator 56 can be mounted directly to the drill bit36. For instance, the indicator 56 can be an LED light that is embeddedin a groove on or otherwise attached to the drill bit 36. Thus, as thedrill bit 36 rotates, the indicator 56 can appear to be a continuousring of light such that the indicator 56 is fairly easy to see for theuser. However, the indicator 56 could be incorporated within the display46 or in any other suitable location without departing from the presentdisclosure. The feedback signal provided by the indicator 56 can betriggered by the alignment system 38.

Thus, as shown in FIG. 2, when the alignment system 38 detects that thedrill bit 36 is misaligned and spaced away from the plug 32 (as shown inphantom), the indicator 56 will not provide the feedback signal.However, when the alignment system 38 detects that the drill bit 36 issubstantially aligned with the plug 32, the indicator 56 can provide thefeedback signal. In some embodiments, the indicator 56 can providemultiple feedback signals. For instance, the indicator 56 can provide afirst feedback signal (e.g., a red light) when the drill bit 36 isspaced far away from the plug 32, the indicator 56 can provide a secondfeedback signal (e.g., a yellow light) when the drill bit 36 is close,but axially misaligned from the plug 32, and the indicator 56 canprovide a third feedback signal (e.g., a green light) when the drill bit36 is axially aligned with the plug 32. Thus, the feedback device 54 canconveniently indicate to the user that the drill bit 36 is in alignment.

Furthermore, the system 10 can include a power generator 58. The powergenerator 58 can be of any suitable type, such as a piezoelectricdevice. The power generator 58 can generate power due to rotation of thedrill bit 36, and the generated power can be used to power theultrasound system 45, the feedback device 54, the indicator 56, thealignment system 38, or any other suitable component of the system 10.In some embodiments, a commercially available drill bit 36 can beretrofitted with the power generator 58.

Thus, during use, the plug 32 can be secured to the rod 16, and the rod16 can be implanted into the resected bone 14. Then, the drill bit 36can be moved relative to the bone 14 until the indicator 56 indicatesthat the drill bit 36 is in alignment with the openings 24 and the plugs32 therein. Then, the user can drill through the bone 14 and embed thedrill bit 36 into the plug 32. Further rotation of the drill bit 36 cancause the plug 32 to back out of the opening 24, as described above, andthe plug 32 can be fully removed from the rod 16 and the bone 14. Insome embodiments, the drill bit 36 only partially removes the plugs 32and a separate tool is used to fully remove the plugs 32 from the rod 16and bone 14. Once the plugs 32 are removed, the drill bit 36 or anotherdrill bit can be advanced into both the bone 14 and the openings 24 toprovide full clearance for the fasteners 30. It will be appreciated thatthe holes created by the drill bit 36 for removing the plugs 32 can beused as a pilot hole for creating holes for the fasteners 30.

Accordingly, the system 10 can allow the user to quickly and accuratelylocate the openings 24 in the rod 16. Moreover, the drill bit 36 can beused to remove the plugs 32. As such, fewer tools are needed to locatethe openings 24 and provide access to the openings 24.

Referring now to FIGS. 5 and 6, additional exemplary embodiments of thepresent disclosure will be discussed. Components that are similar to theembodiments of FIGS. 1-4 are identified with corresponding referencenumerals increased by 100. It will be appreciated that the componentsillustrated in FIGS. 5 and 6 can include similar features, can be madeout of similar materials, and can provide similar advantages as thosedescribed above. Those details will not be repeated here; however, theembodiments of FIGS. 5 and 6 can include additional features as well,including those discussed below.

FIG. 5 shows an exemplary embodiment of the plug 132 before beinginserted into the opening 124 of the rod 116. As shown, the plug 132 canbe axially tapered. For example, the plug 132 can include a first end160 and a second end 162, and the plug 132 can gradually taper down inwidth from the first end 160 to the second end 162. Also, the plug 132can include a thread 165. As shown, the pitch of the thread 165 can besignificantly higher than threading 167 on the inner surface 166 of theopening 124 in the rod 116.

Thus, when the second end 162 of the plug 132 is inserted and advancedinto the opening 124 (indicated by an arrow in FIG. 5), the thread 165can guide movement of the plug 132 into the opening 124, and the taperedouter surface 164 of the plug 132 can abut against the inner surface 166of the opening 124 to center the plug 132 within the opening 124.Accordingly, inserting the plug 132 into the rod 116 can be facilitated.

As shown in FIGS. 5 and 6, the outer surface 164 of the plug 132 can beat least partially deformable. For instance, the plug 132 can be made ofa biocompatible material that is softer than that of the rod 116, andthe outer surface 164 adjacent the first end 160 can plastically deformagainst the inner surface 166 of the opening 124 upon insertion of theplug 132 into the opening 124. For instance, the outer surface 164 canplastically deform into the threading of the inner surface 166 of theopening 124 to securely engage the rod 116. In other embodiments, theplug 132 can elastically deform against the inner surface 166 of theopening 124 upon insertion of the plug 132.

Furthermore, because of the tapered outer surface 164, only a portion ofthe plug 132 (i.e., the portion adjacent the first end 160, separated bya vertical line in FIG. 6) engages the inner surface 166 of the taperedplug 132. As a result, the plug 132 can be easier to disengage andremove from the rod 116. Also, the plug 132 is unlikely to disengagefrom or be stripped by the removal tool 34 (FIGS. 3 and 4) because theplug 132 can disengage from the rod 116 with less resistance.

In addition, in some embodiments, the thread 165 of the plug 132 and/orthe threading 167 of the opening 124 can have a significantly highthread pitch. For instance, the thread pitch can be high enough suchthat backing out the plug 132 of the opening 124 and disengaging theplug 132 from the rod 116 can be accomplished simply by rotating theplug 132 less than one full rotation about its axis.

Referring now to FIGS. 7 and 8, additional exemplary embodiments of thepresent disclosure will be discussed. Components that are similar to theembodiments of FIGS. 1-4 are identified with corresponding referencenumerals increased by 200. It will be appreciated that the componentsillustrated in FIGS. 7 and 8 can include similar features, can be madeout of similar materials, and can provide similar advantages as thosedescribed above. Those details will not be repeated here; however, theembodiments of FIGS. 7 and 8 can include additional features as well,including those discussed below.

FIG. 7 shows another exemplary embodiment of the plug 232 before beinginserted into the opening 224 of the rod 216. As shown, the plug 232 canbe substantially helical and resiliently deformable. For instance, theplug 232 can helically wind about its axis to define an inner space 271therein. Also, the plug 232 can have a width W that is greater than awidth W′ of the opening 224.

As such, when the plug 232 is inserted into the opening 224 (asindicated by an arrow in FIG. 7), the helical plug 232 can elasticallyand resiliently deform, reducing in width, to be retained securelywithin the opening 224.

Furthermore, to remove the plug 232, the removal tool 34 discussed aboveand shown in FIGS. 3 and 4 can at least partially enter the inner space271 and engage the plug 232 (not specifically shown). As such, engagingthe plug 232 for removal can be facilitated.

Referring now to FIG. 9, additional exemplary embodiments of the presentdisclosure will be discussed. Components that are similar to theembodiments of FIGS. 1-4 are identified with corresponding referencenumerals increased by 300. It will be appreciated that the componentsillustrated in FIG. 9 can include similar features, can be made out ofsimilar materials, and can provide similar advantages as those describedabove. Those details will not be repeated here; however, the embodimentsof FIG. 9 can include additional features as well, including thosediscussed below.

As shown, the plug 332 can have an auger-type shape. For instance, theplug 332 can have a central rod 381 and a blade 383 that helically windsabout the rod 381, similar to an auger. The shape of the plug 332 canfacilitate coupling and de-coupling of the plug 332 because of thesubstantially small surface area contact with the rod 16, 116, 216.

Moreover, the foregoing discussion discloses and describes merelyexemplary embodiments of the present disclosure. One skilled in the artwill readily recognize from such discussion, and from the accompanyingdrawings and claims, that various changes, modifications and variationsmay be made therein without departing from the spirit and scope of thedisclosure as defined in the following claims. For instance, thesequence of the blocks of the method described herein can be changedwithout departing from the scope of the present disclosure.

What is claimed is:
 1. A method of implanting a prosthetic device into abone comprising: inserting the prosthetic device into the bone, theprosthetic device including an opening and a plug removably receivedwithin the opening; detecting whether a bone removal tool disposedoutside the bone and the plug are substantially axially aligned;advancing the bone removal tool from outside the bone into the bone toremove a portion of the bone and to reveal the plug; engaging the boneremoval tool and the plug; and removing the plug from the opening of theprosthetic device at least partially while the bone removal tool isengaged with the plug.
 2. The method of claim 1, further comprisingthreadably engaging the plug to the prosthetic device within the openingof the prosthetic device.
 3. The method of claim 2, wherein the plugthreadably engages the prosthetic device in a first rotationaldirection, and wherein removing the plug from the opening includesrotating the bone removal tool in a second rotational direction that isopposite the first rotational direction.
 4. The method of claim 1,wherein detecting whether the bone removal tool and the plug aresubstantially axially aligned includes generating an ultrasound signalfrom outside the bone, and distinguishing an ultrasonically detectablematerial of the plug from an area adjacent the ultrasonically detectablematerial.
 5. The method of claim 1, wherein the bone removal toolincludes a drill bit, and further comprising generating power fromrotation of the drill bit to power an alignment system that detectswhether the bone removal tool and the plug are substantially axiallyaligned.
 6. The method of claim 1, wherein detecting whether the boneremoval tool and the plug are substantially axially aligned includesemitting a radio frequency (RF) signal from an emitter operably coupledto one of the plug and the bone removal tool, receiving the RF signal bya receiver operably coupled to the other of the plug and the boneremoval tool, and processing the RF signal received by the receiver todetect whether the bone removal tool and the plug are substantiallyaxially aligned.
 7. The method of claim 1, further comprising providinga feedback signal to indicate that the bone removal tool issubstantially axially aligned with the plug.
 8. The method of claim 7,wherein providing the feedback signal includes providing at least one ofa visual, audible, and tactile feedback signal.
 9. The method of claim1, wherein inserting the prosthetic device includes inserting anintramedullary rod into an intramedullary canal of a femur, a tibia, ora humerus.
 10. The method of claim 1, further comprising removablyinserting the plug into the opening of the prosthetic device, anddeforming an outer surface of the plug against an inner surface of theopening while inserting the plug into the opening.
 11. The method ofclaim 10, wherein deforming the outer surface includes plasticallydeforming the outer surface of the plug against an inner surface of theopening while inserting the plug into the opening.